A building entrance protector, i.e. junction box, provides an interface for cables from the central office of the service provider for distribution to subscribers throughout the building served by the junction box. Numerous cables and wires enter and exit a junction box through openings on the sidewalls. When the capacity of the building entrance protector and/or the number of subscribers in the building increase, one or more additional building entrance protector may be added to accommodate additional cables from the central office.
Cables and/or wires in the additional junction box interact with the original junction box via openings on the boxes. Cables and/or wires traversing openings of a junction box are subject to chafing against the edges of the openings. This problem is amplified for sheet metal junction boxes, where the sharp edges of the openings may pierce through the insulated coating of cables and/or wires over time, resulting in a short or severe the cables and/or wires, resulting in complete failure of the equipment.
To protect cables and/or wires from chafing against the edges of openings of junction boxes, a rubber annular ring grommet is used to cover the sharp edges. The annular ring grommet has a radial groove defined by a pair of radial lips that fit over the circular edge of the opening. Each of the radial lips sit on and advantageously resiliently engage opposite surfaces of the sidewall surrounding the opening and maintain the grommet in position.
For outdoor environment, the additional junction box is stacked vertically on top of and abutting the existing box to limit the amount of undesired elements from entering the junction boxes. External elements such as water, insects, dust, etc. may interfere with the proper operation of the electrical equipment located in a junction box, which may result in complete failure of the equipment. Vertically stacked boxes allow cables and/or wires to traverse their openings vertically which limit some undesired elements from entering the lower box. However, by merely stacking one junction box on top of another cannot effectively prevent all undesired elements, especially water, from entering the lower junction boxes.
U.S. Pat. No. 5,550,916 discloses a stackable junction box particularly suited for outdoor use. Junction box 10 provides openings 37 and 38 for cables and/or wires to traverse from openings 47 and 48 of a corresponding junction box stacked on top of junction box 10. Around the periphery of the top surface 31 is a strip of sealing material 36 which prevents undesired elements from entering openings 37, 38, 47 and 48 of junction box 10 when two boxes are stacked. Upon stacking a corresponding junction box on top of junction box 10, the upper box is compressed against the sealing material 36 of the lower box 10 to provide a sealed interface between two vertically stacked junction boxes. U.S. Pat. No. 5,550,916 discussed herein is hereby incorporated by reference as background of the invention.
Although junction box 10 disclosed in U.S. Pat. No. 5,550,916 provides a sealed interface between two vertically stacked junction boxes, it requires the manufacturing of special boxes having sealing material 36, which can be costly. Furthermore, compression of two vertically stacked junction boxes is time consuming to a service technician and may not be achievable if the additional box cannot physically be stacked vertically abutting the lower box due to the surrounding area of the junction box.
To properly seal the interface between two stacked junction boxes and protect the cables and/or wires traversing the two boxes can be costly and time consuming because a service technician must replace existing boxes and maneuver a separate grommet. Therefore, there is a need for a device that seals the interface between two adjacently stacked junction boxes and protects cables and/or wires traversing openings of the two boxes in a cost-effective manner.